According to Laura Hautala’s article in the C|Net web site, some apps may track your activity over time, even when you tell them to forget the past. And there’s nothing you can do about it.
The apps can track you by linking your Advertising ID — a unique but resettable number used to tailor advertising — with other identifiers on your phone that are difficult or impossible to change. Those IDs are the device’s unique signatures: the MAC address, IMEI and Android ID. Less than a third of the apps that collect identifiers take only the Advertising ID, as recommended by Google’s best practices for developers.
“Privacy disappears” when apps collect those persistent identifiers, said Serge Egelman, who led the research.
Egelman said his team, which reported the findings to Google in September, observed most of the apps sending identifying information to advertising services, an apparent violation of Google’s policies.
Sandy Bilus, a privacy and cybersecurity lawyer at Saul Ewing Arnstein & Lehr, said the apps might be in violation of the General Data Protection Regulation, a European Union law that requires organizations to tell users what data they collect on them, if they haven’t spelled out what they’re collecting to EU users.
You can read a lot more about this issue at: https://cnet.co/2TQcafu.